That does nothing to answer how someone existing on this earth here and now who is dead in traspasses and sins can in and of themselves hear the Words of Christ.
I disagree with your definition of dead.
I don’t know of a verse that says man is born hardened (please call it out if I missed it.)
Man is not born with a hardened heart but can do this to himself over time. This can
then make them fit Mark 4:12 description (seeing but never perceiving etc) but man is
not pre-depositioned to this at birth, we sin due to the fall of Adam but are not seared with hardness at birth due to it.
Hebrews 3:15, Romans 1:28, 1 Timothy 4:2
As for salvation? The gift of salvation is all from His grace and mercy but a person freely chooses to either accept or decline. I think the
gospel itself is the grace with which the Holy Spirit works through - it enables those who hear it. Nothing more, God does not force people. Some rebel, with enough rebellion their hearts harden as God gives them “up” to their desires (Paul uses this term 3 times in Romans 1)
“But as for you, continue in what you have learned and have become convinced of, because you know those from whom you learned it, and
how from infancy you have known the Holy Scriptures, which are able to make you wise for salvation through faith in Christ Jesus.”
2 Timothy 3:14-15 NIV
https://www.bible.com/111/2ti.3.14-15.niv
“Jesus performed many other signs in the presence of his disciples, which are not recorded in this book. But these are written
that you may believe that Jesus is the Messiah, the Son of God, and that by believing you may have life in his name.”
John 20:30-31 NIV
My 2 cents